In this section, we will use fMRI to explore the processing of auditory patterns at both low and high level of complexity: from the fusion of harmonics to the expectations involved in musical sequences. Our primary aim is to contrast the processing of patterns that conform to familiar constraints with patterns that violate these constraints. Patterns that conform to familiar constraints are often heard as Gestalts, suggesting that neural circuits that have adapted to them integrate their features into a perceptual whole. Familiar patterns may also generate sequential expectations based on their transitional probabilities. Among the patterns we will study are harmonic complex tones, octaves, chords, sequences of tones, and sequences of chords. Related issues will investigate include: the violation of sequential expectations; the perceptual completion of incomplete patterns (as in the perception of harmonic complex tones missing their fundamental frequencies); changes in processing as unfamiliar patterns are learned; and possible differences between familiar musical patterns that lack transparent semantic content with familiar environmental sounds that have clear referents. These results are expected to shed light on the cortical representation and processing of patterns at various levels of complexity, and as a function of familiarity and as a function of the nature of the constraints they embody.